HV8DC - 8 DC port protection

This is a specially designed board to protect up to 8 DC control wires. The connection between the control box and the equipment outside (on the mast) can be dangerous. During a storm, a potential difference can easily arise or voltage can be induced on the control wires - this voltage needs to be safely routed to a common ground potential to protect the equipment behind the protection.

This protection includes Gas Discharge Tubes (GDT) between the individual control wires and the ground screw and also from the individual wires to the GND terminal. The ground screw is for the common ground-lead connection. Also marked GND on the terminal block is the ground for the equipment and control box. Between these ground points is again a protective GDT. There are two different GNDs - the GND of the control wires and the GND of the screw. The GND screw is for the surge lead to the common ground potential.

Functional description:

The wire from the external environment comes to the terminal and is fed to the high voltage bridge - a thin wire in the function of a fuse. From there it is connected via a capacitor and GDT (75V) to the GND screw. It then goes to the low pass filter and GDT (75V), where it already shares a common GND with the GND terminal on the connector. The low pass filter consists of capacitors and embedded inductance. Behind the LPF is a DC transil with a clamping voltage of about 40V DC, in the opposite way it works as a diode. In parallel with the transil is a LED indicating the voltage on the pin. The input terminal is connected in series with a reset fuse.

⚠ CAUTION, IMPORTANT!
This board is unlikely to protect your equipment from being destroyed by a direct lightning strike. Minimising the effects of lightning is a more complex problem and requires a more comprehensive approach.

This board is designed to provide surge suppression and additional protection for indoor equipment. If more energy is discharged, this board may be damaged - shorting out the protection element.